Link boxes are used where it is desired temporarily to interrupt the supply of electric current in a cable or cables, e.g., a three-phase AC mains supply. Such boxes may be installed in underground chambers in roadways or other paved areas. A link box is interposed between two parts of a cable and serves to either permit or interrupt the flow of current along the cable. In such a case, the link box contains two sets of terminals, for the individual cores of the two parts of the cable, and a set of mechanical links are used to connect the corresponding terminals to complete the current path. Physical removal of the link interrupts the flow of current. More complex arrangements are also possible in which a number of cables are connected to a link box and a variety of possible connections can be achieved by the use of appropriate links.
An exemplary link box 10 is illustrated in FIG. 1. The link box 10 includes a housing 12 having a base panel 14 with opposite first and second walls 16a, 16b and opposite third and fourth walls 18a, 18b extending outwardly therefrom to form an enclosure 20. A panel 22 (FIG. 2) can be secured to the housing 12 to cover the enclosure 20. The housing 12 and panel 22 are typically formed from metal, such as stainless steel.
Within the enclosure 20 of the illustrated link box 10 are a plurality of sheath voltage limiters (SVLs) 30 to which electrical cables 40 are connected, as illustrated in FIG. 2. These cables 40 extend into the enclosure 20 via respective metal ports 50 in wall 16a. Each cable 40 is sealed to a metal port 50 via heat shrink tubing 60, as illustrated in FIG. 3. As shown in FIG. 3, a heat source H provides heat necessary to shrink the heat shrink tubing around each respective cable 40 and port 50.
To disconnect a cable 40 from a conventional link box, such as box 10 of FIGS. 1-2, a user must cut off the heat shrink tubing 60 from around the metal ports 50. Unfortunately, this may be time consuming and inconvenient for a technician, typically out in the field.